just open the glove compartment and the option code NPP will be listed. A less intensive option would be to look for the venturi valve equipment out back

Exactly. The VIN will tell you nothing about options. From 2010 on the VIN will tell you what base packages (1LT, 2LT, etc.), GS, Z06, and ZR1 packages. All other options can be found on the glove box decal or a build sheet/window sticker if you have one.

If your inner exhaust tips have the butterfly valve, the car has NPP. Whether it is factory optioned or owner added can only be told by the option sheet.

Heck you can tell if a vette has NPP and the fuse pulled from a distance. Just look at the inside pipes. If they're blacker than the outside ones, the car has NPP and the fuse is pulled (or M2W, or a 2 dollar switch like I have).

New '13 GS owner with the NPP option. Asking the question: Is the valve operated by solenoid or vacuum? In reading a few threads, it sounds like there is a way to open the valve all the time vs just above 3K RPM with heavy foot. Simple fix? Pulling the fuse doesn't send a code to the ECU?

So I gotta ask: Is the non-NPP (standard) exhaust like the NPP option in quiet mode? Or full open mode? If the latter, why do dealers order the extra cost NPP option only to have new owners immediately disable it?

NPP valves on the mufflers are controlled by vacuum. My car didn't come with it but i used the aftermarket ones from B&B and routed the hoses, etc. The B&B sound similar to normal exhaust when the valves are closed and louder when open. Some people disable them and keep them loud all the time...others prefer to be able to control them when they want. Also by using one of the aftermarket switches you can control it manually vs. hitting the RPMs, etc.

NPP... the best option I never knew I wanted. Absolutely love mine, although I would very highly recommend either a mild to wild controller or some sort of a hardwired switch so that you have total control of the NPP baffles.

They are very easy to spot if you look at an exhaust from behind. The solenoids above the mufflers stick out like a sore thumb. Some people cover them although I personally like them.

Still looking to buy my first vette. Is there a way to tell if a c6 is equipped with the NPP exhaust option by VIN number?

If buying used, as mentioned, simply bend down and look for the valve actuators on the pipe coming out from the mufflers. If new, it will be listed as an option on the window sticker. Also, the exhaust tips are slightly larger on the NPP vs the base non NPP exhaust.

NPP... the best option I never knew I wanted. Absolutely love mine, although I would very highly recommend either a mild to wild controller or some sort of a hardwired switch so that you have total control of the NPP baffles.

NPP valves on the mufflers are controlled by vacuum. My car didn't come with it but i used the aftermarket ones from B&B and routed the hoses, etc. The B&B sound similar to normal exhaust when the valves are closed and louder when open. Some people disable them and keep them loud all the time...others prefer to be able to control them when they want. Also by using one of the aftermarket switches you can control it manually vs. hitting the RPMs, etc.

And I read that the C7 will use some sort of electronic acutator for the NPP.